Dion Phaneuf committed a critical error that led to Boston taking a 3-1 series lead. David Krejci — with his third goal of the night — administered the coup de grace that started all this nonsense at 13:06 of overtime, squeezing a puck through James Reimer on a two-on-one created by Phaneuf’s eagerness to pinch in to try and thump Nathan Horton at the other end of the ice.

In overtime, Phaneuf got a piece of the Bruins forward but in so doing allowed Krejci and Milan Lucic to head towards the Leafs goal with just Ryan O’Byrne in their way. Krejci used Lucic as a decoy, then snapped a shot past Reimer.

“You can’t afford to make mistakes that lead to odd-man rushes,” said Leafs coach Randy Carlyle. “We turned the puck over deep in the corner and then we pinched and gave them an odd-man rush and they scored a short-side goal to beat us and that’s kind of a dagger, it feels like a dagger after the effort that was put forth by our group.

Said Phaneuf: “I take responsibility for making a bad play. I said that and I don’t know what more you guys want me to say. I made a bad play and it cost us the game.”

The Leafs now face a potentially decisive Game 5 in Boston, where history and the Bruins are against them.